From: Dmitry Frolov <fro...@swemel.ru> A crash found while fuzzing device virtio-net-socket-check-used. Assertion "offset == 0" in iov_copy() fails if less than guest_hdr_len bytes were transmited.
Signed-off-by: Dmitry Frolov <fro...@swemel.ru> Message-Id: <20240613143529.602591-2-fro...@swemel.ru> Reviewed-by: Michael S. Tsirkin <m...@redhat.com> Signed-off-by: Michael S. Tsirkin <m...@redhat.com> --- hw/net/virtio-net.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 9c7e85caea..8f30972708 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -2735,6 +2735,10 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q) */ assert(n->host_hdr_len <= n->guest_hdr_len); if (n->host_hdr_len != n->guest_hdr_len) { + if (iov_size(out_sg, out_num) < n->guest_hdr_len) { + virtio_error(vdev, "virtio-net header is invalid"); + goto detach; + } unsigned sg_num = iov_copy(sg, ARRAY_SIZE(sg), out_sg, out_num, 0, n->host_hdr_len); -- MST